Which medication is indicated for the treatment of MRSA infections?

Vancomycin is the medication of choice for the treatment of Methicillin-Resistant Staphylococcus Aureus (MRSA) infections. MRSA has developed resistance to beta-lactam antibiotics, which include drugs such as nafcillin and oxacillin. These antibiotics are effective against methicillin-sensitive Staphylococcus aureus (MSSA), but they are not suitable for MRSA due to the presence of the mecA gene, which alters the target of these drugs, rendering them ineffective.

Vancomycin, on the other hand, works by inhibiting bacterial cell wall synthesis through binding to the D-alanyl-D-alanine portion of cell wall precursors. This mechanism is unaffected by the resistance mechanisms employed by MRSA, making vancomycin a key treatment option for serious MRSA infections, particularly in skin and soft tissue infections, pneumonia, and bloodstream infections.

Demeclocycline is part of the tetracycline class and while it has some antibacterial activity, it is not specifically indicated for MRSA and is typically not among the first-line treatment options for such infections. Thus, vancomycin is the correct choice among these options for treating MRSA.